Chain making apparatus

ABSTRACT

A chain making plant in which at least one arm is supported by a central supporting structure for rotation about a vertical axis so as to successively present a depending portion of a chain supported by the arm to a number of operating stations distributed around said control structure, said operating stations serving successively to add a link to the chain and to perform the operations required to finish said link. A conveyor provided on the arm serves to discharge the chain step by step into a vertical passage near said vertical axis, and additional means are provided to guide and advance the chain along a path extending from the lower extremity of said passage to a discharge point located further away from the central supporting structure than said operating station.

United States Patent Andreasson et al.

CHAIN MAKING APPARATUS [72] Inventors: Per Arvid Andreasson; Mats 0101 Persson, both of Laxa, Sweden [73] Assignee: Elektriska Svetsningsaktiebolaget,

Gothenburg, Sweden [22] Filed: Feb. 16, 1971 21 Appl.No.: 115,326

[30] Foreign Application Priority Data June 18, 1970 Sweden ..8477/70 [52 us. or "59/16, 59/32 [51] Int.Cl. ..B2ll5/02 [58] Field of Search ..59/16, 1, 3, 25, 31, 32, 35

[56] References Cited UNITED STATES PATENTS 919,487 4/1909 Standish ..59/l6 2,242,164 5/1941 Barstow ..59 /31 3,355,876 12/1967 Oettinger ..59/35 [,8 M a 13 fi 20a [151 3,701,251 [451 Get. 31, 1972 Primary Examiner-Charles Lanham Assistant Examiner-Gene P. Crosby Attorney-Cameron, Kerkam & Sutton [57] ABSTRACT A chain making plant in which at least one arm is supported by a central supporting structure for rotation about a vertical axis so as to successively present a de-' pending portion of a chain supported by the arm to a number of operating stations distributed around said control structure, said operating stations serving successively to add a link to the chain and to perform the operations required to finish said link. A conveyor provided on the arm serves to discharge the chain step by step into a vertical passage near said vertical axis, and additional means are provided to guide and advance the chain along a path extending from the lower extremity of said passage to a discharge point located further away from the central supporting structure than said operating station. I

8 Claims, 3 Drawing Figures CHAIN MAKING APPARATUS This invention relates to apparatus for making chain.- More particularly, the invention relates to chain making apparatus of the type comprising means for succestion is raised by an amount corresponding to the pitch of the chain to permit the hooking on and finishing of another link, etc. Still more particularly, the invention is concerned with apparatus of the type specified in which the operating stations referred to are distributed around a circular course and in which the means for successively presenting the depending chain portion to said stations comprise a supporting structure at the center of said circular course, a movable arm mounted on said central supporting structure for rotation about a vertical axis, and conveyor means provided on said arm for guiding and advancing the chain from a first point at which the topmost link of the depending portion of the chain enters the conveyor to a second point near the vertical axis of rotation of the arm.

In existing chain making plants of this kind, the movable arm is rotated in one direction only, and the chain successively discharged at the inner end of the conveyor means is collected by a bin provided at the foot of the central supporting structure, said bin being placed on a rotary platform or the like to allow for the rotation imparted to the chain by the movable arm. To utilize the operating stations as fully as possible, the plants are provided with a plurality of arms (more particularly, either two or four arms) serving the same group of operating stations, each of which arms carries a separate chain.

With present plants of the type above outlined, the limited capacity of the take-up bin prevents the manufacture of long continuous lengths of heavy chain, for instance anchoring chains of the size and length required for floating oil boring platforms. Also, price and space considerations practically exclude the possibility of fitting out a plant of the type referred to with a rotary receptacle big enough to hold long large-size chains.

The present invention provides a chain plant of the general type above specified which, while retaining the basic advantages of said type of plant, permits the manufacture of any continuous length of chain. According to a principal feature of the invention, there are provided additional means for guiding and advancing the chain along a path extending from a point below the exit end of the conveyor means provided on the arm to a discharge point located further away from said vertical axis than the operating stations.

Other features and advantages of the invention will appear from the following description and from the accompanying drawings representing somewhat schematically a preferred embodiment of the invention, in which F IG. 1 is a plan view of the chain making apparatus,

FIG. 2 is a side view of the apparatus, some parts being shown in section on the line IIII of FIG. 1, and,

FIG. 3 is a schematized side view of the complete chain making plant including the means for successively conveying the chains to a receptacle.

A circular rail 1 is supported above the shop floor 3 on pillars 2. In FIG. 2, all but two of said pillars have been left out in order not to clutter up the figure/A number of operating stations comprising a bending machine 6, a flash welder 7, a weld trimmer 8 and a I stud press 9 are mounted on the shop floor below the circular rail 1 in locations equally spaced around said rail. In addition, the apparatus comprises, a bar stock heater 4 and a roller conveyor 5 for the heated bar stock. The units 4 to 9 are represented schematically only and need not be described in detail, all of them being well known in the chain making art. An arm 10 is supported at one end by a bearing member 15 rotatably supported by a hollow column 14 located centrally in respect of the rail 1, and at the other end by a carriage 12 running on the rail 1. A second arm 11 is supported at one end by a bearing member 16 rotatably supported by the column 14 independently of the bearing member 15, and at the other end by a carriage 13 running on the rail 1. Each of the carriages is provided with a reversible driving unit 17, 18 by means of which the arm can be moved to any desired angular position under the control of an operator. Each of the arms is' provided with a conveyor comprising a pair of chain wheels 19a, 19b and 20a, 20b, respectively, and a driving unit 21, 22, respectively. The tubular column 14 is opentop and bottom. The bottom end of the column opens into a chamber 23 provided below the shop floor and constituting the entrance to a channel 24 connecting said chamber to an opening in the shop floor located outside the group of operating station 6-9 and adjacent to a chain wheel 28 constituting the first element of a conveyor comprising the chain wheels 28, 29, 30 and 31 by means of which the chain is advanced to a lighter 32.

The plant also includes apparatus for subjecting the chains to various operations during their passage through the conveyor, to wit, a tunnel furnace 25 for normalizing the chain links, a tensile strength testing machine 26 for checking the strength of the chain links, and a chain link surfacing station 27, in which the chain links are given a coating of asphalt.

The operation of the apparatus shall now be described with reference to the chain 34 supported by the arm 11. It is assumed that said arm has just been swung back clockwise through three-quarters of a turn from the station 9 to the station 6. A piece of bar stock of the proper length heated in the heater 4 to the temperature required for the subsequent bending operation is moved along the roller conveyor 5 to the bending machine 6, in which it is bent into a C-shaped lug hooked on to the lowermost link of the portion of a chain 34 which depends from the chain wheel 20a. The bending machine also subjects said lug to the final bending operation required to make its ends meet. The arm 11 is then rotated anti-clockwise a quarter of a turn by means of the driving unit 18 so as to present the link just formed to the next operating station constituted by the flash welder 7. On completion of the welding operation, the arm 11 is rotated a further quarter of a turn to the weld trimmer 8, in which the quarter-turn to the stud press 9 in which a stud is pressed into position between the shanks of the link. The depending portion of the chain 34 is now raised by the length, or pitch, of one link by means of the driving unit 22 operating the chain wheels 20a, 20b. The arm 11 is then swung back clockwise three-quarters of a turn to the station 6, and the same sequence of operations is repeated. V

'A similar sequence of operations is performed with the aid of the arm 10. The relative displacements of the arm l0, 11 should be carried out so as to utilize the capacity of the apparatus as fully as possible. In the manufacture of extra heavy chains (made from bar stock of diameters 4 in. to 7 A in), the time required by the operations at station 6 (including the heating of the bar stock) approaches the total time required by the stations 7, 8 and 9. In that case, the displacements of the arm are preferably performed according to the following schedule. The plus sign denotes a counterclockwise rotation of one quarter-turn, while the minus sign denotes a clockwise rotation of three-quarters of a turn.

OPERATING STATION The periodic rotation of each of the arms 10, 11 through an arc of 270- first in one direction and then in the other direction subjects the top link of the part of the chain depending through the vertical passage in the central column 14 to a corresponding rotation about a vertical axis. The length of said depending portion and, thence, of the vertical passage has to be large enough to allow said depending portion to take up the resulting torsion. The chain may be drawn off from the chamber 23 either continuously or step by step by means of the conveyor 28-31. In any case, the withdrawal should be adjusted in such a way as to allow a few links to rest loosely upon the floorof the chamber 23.

Separate receptacles may, of course, be provided for each of the chains instead of the common receptacle 32 shown.

in the preceding description, various details not required for the understanding of the invention have been omitted. For instance, each of the arms may be provided with manipulating equipment for rotating the lowermost link of the portion of the link depending from the outer end of the arm into the proper position for receiving the lug which is to form the next link. Also, special manipulating equipment may have to be provided at the station 6 to handle the red hot piece of bar stock the weight of which may amount to 1,000 lbs.

or more.

We claim:

1. in a chain making plant comprising means for suc cessively presenting a depending end portion of a chain previously formed to a plurality of operating stations for performing a succession of operations including hooking a C-shaped lug on to the lowest link of said depending portion, closing said C-shaped ing to form a link, and welding and trimming the joint of said link, said operating stations being distributed around a circular course, said means comprising a supporting structure at the center of said circular course, a movable arm mounted on said central supporting structure for rotation about a vertical axis, and conveyor means provided on said arm for guiding and advancing the chain from a first point at which the topmost link of the depending portion of the chain enters the conveyor to a second point near the vertical axis of rotation of the arm, the improvement which comprises additional means for guiding and advancing the chain along a path extending from a point located vertically below said second point to a discharge point located further away from said vertical axis than the operating stations.

2. A chain making plant as claimed in claim 1 in which said central structure encloses a vertical channel 4 ,open top and bottom to accommodate a vertical length of chain extending between said second point and the admittance end of said path.

3. A chain making plant as claimed in claim 1 comprising a floor or platform providing access to the operating stations, in which said path extends through a passage provided below the level of said floor or platform.

4. A chain making plant as claimed in claim 1 which further comprises a tunnel furnace enclosing part of said path.

5. A chain making plant as claimed in claim 1 which further comprises a chain link surfacing station enclosing part of said path.

6. A chain making plant as claimed in claim 1 which further comprises a tensile strength testing device for successively checking the strength of links advanced along said path.

7. A chain making plant as claimed in claim 1 which comprises at least one additional arm and individual bearing means for supporting said arm on said central supporting structure for rotation about said vertical axis, whereby the arms are angularly adjustable about said axis independently of each other, conveyor means provided on said additional arm for guiding and advancing a second chain from an outer point the radial distance of which to said vertical axis is equal to the radius of said circular course, to an inner point near said vertical axis, and means for guiding and successively advancing the chain along a path extending from a point located vertically below said inner point to a discharge point located further away from said vertical axis than the operating stations.

8. A chain making plant comprising means for successively presenting a depending end portion of a chain previously formed to a plurality of operating stations for performing a succession of operations including hooking a C-shaped lug on to the lowest link of said depending portion, closing said C-shaped lug to form a link, and welding and trimming the joint of said link, said operating stations being distributed around a circular course, said means comprising a supporting structure at the center of said course, bearing means provided at the top portion of said supportingstructure for rotation about a vertical axis, a radial arm attachedto said bearing means, a carriage attached to the outer extremity of said radial arm, a circular track for said carriage at a level above said operating stations, reversible drive means on said carriage, and conveyor means on said arm for guiding and advancing the chain from a first point at which the topmost link of the depending portion of the chain enters the conveyor to a second point near the vertical axis of rotation of the arm. 

1. In a chain making plant comprising means for successively presenting a depending end portion of a chain previously formed to a plurality of operating stations for performing a succession of operations including hooking a C-shaped lug on to the lowest link of said depending portion, closing said C-shaped lug to form a link, and welding and trimming the joint of said link, said operating stations being distributed around a circular course, said means comprising a supporting structure at the center of said circular course, a movable arm mounted on said central supporting structure for rotation about a vertical axis, and conveyor means provided on said arm for guiding and advancing the chain from a first point at which the topmost link of the depending portion of the chain enters the conveyor to a second point near the vertical axis of rotation of the arm, the improvement which comprises additional means for guiding and advancing the chain along a path extending from a point located vertically below said second point to a discharge point located further away from said vertical axis than the operating stations.
 2. A chain making plant as claimed in claim 1 in which said central structure encloses a vertical channel open top and bottom to accommodate a vertical length of chain extending between said second point and the admittance end of said path.
 3. A chain making plant as claimed in claim 1 comprising a floor or platform providing access to the operating stations, in which said path extends through a passage provided below the level of said floor or platform.
 4. A chain making plant as claimed in claim 1 which further comprises a tunnel furnace enclosing part of said path.
 5. A chain making plant as claimed in claim 1 which further comprises a chain link surfacing station enclosing part of said path.
 6. A chain making plant as claimed in claim 1 which further comprises a tensile strength testing device for successively checking the strength of links advanced along said path.
 7. A chain making plant as claimed in claim 1 which comprises at least one additional arm and individual bearing means for supporting said arm on said central supporting structure for rotation about said vertical axis, whereby the arms are angularly adjustable about said axis independently of each other, conveyor means provided on said additional arm for guiding and advancing a second chain from an outer point the radial distance of which to said vertical axis is equal to the radius of said circular course, to an inner point near said vertical axis, and means for guiding and successively advancing the chain along a path extending from a point located vertically below said inner point to a discharge point located further away from said vertical axis than the operating stations.
 8. A chain making plant comprising means for successively presenting a depending end portion of a chain previously formed to a plurality of operating stations for performing a succession of operations including hooking a C-shaped lug on to the lowest link of said depending portion, closing said C-shaped lug to form a link, and welding and trimming the joint of said link, said operating stations being distributed around a circular course, said means comprising a supporting structure at the center of said course, bearing means provided at the top portion of said supporting structure for rotation about a vertical axis, a radial arm attached to said bearing means, a carriage attached to the outer extremity of said radial arm, a circular track for said carriage at a level above said operating stations, reversible drive means on said carriage, and conveyor means on said arm for guiding and advancing the chain from a first point at which the topmost link of the depending portion of the chain enters the conveyor to a second point near the vertical axis of rotation of the arm. 